Our method was evaluated in vivo using data from eleven healthy volunteers and two patients. For the recruitment and consent of human subjects, the ethical approval was given by an Internal Review Board (2005H0124) at The Ohio State University. Two ten-slice short-axis stacks of RT cine covering the whole heart were acquired for each volunteer on a 1.5 T scanner (MAGNETOM Avanto, Siemens Healthcare, Erlangen, Germany), one under free-breathing and the other under end-expiration BH conditions, respectively. The BH acquisition was performed as a reference for cardiac function quantification.
The acquisition time for each slice was 10 s to cover 1-3 respiratory cycles and 8-14 heartbeats. The slices were acquired sequentially with ECG trigger on. There was a small time gap (less than 1 s) between slices, and the starting respiratory phase for each slice was unknown and arbitrary. The other imaging parameters include: flip angle \(69^{\circ }\) , TE/TR \(1.18/2.83\)  ms, pseudo-random Cartesian sampling with acceleration rate of 9 [1]}, slice thickness 8 mm, interslice gap 2 mm, FOV \(\sim 300\times 400\)  mm, spatial resolution \(1.6\times 1.6\)  mm\(^2\) , and temporal resolution 40–45 ms, resulting in 222–250 frames per slice.
The two patients were scanned using the same protocol, with slightly worse temporal (\(\sim 51\)  ms) and spacial (\(\sim 2\times 2\)  mm\(^2\) ) resolutions on a 1.5 T scanner (MAGNETOM Sola, Siemens Healthcare, Erlangen, Germany) under free-breathing conditions. All the images were reconstructed inline using the Gadgetron [2]} implemention of a parameter-free compressed sensing method called SCoRe [3]}.
